Process for the production of magnesium by means of thermic reduction



Oct. 7, .1941. L. AMAT I 2,258,374 PBOQESS FOR THE PRODUCTION fi lMAGNE$IUM DY MEANS OF THERMIC REDUCTION Filed Jan. 26, 1940 4 :2 h f mPatented Oct. 7, 19 41- NESIUM BY MEANS OF THEBMIO TION REDUC- m1 Amati,Padova, Italy Application January 2c, 1940, Serial No. $15,849 in ItalyJuly 1,1939

1 Claim. (01, 15-6 '1) The present invention relates to a process forthe production of magnesium by thermic reduction, under vacuum orreduced pressure, of magnesium-containing raw materials, by means ofreducers such as silicon, ferro-silicon, aluminum or similar reducingsubstances which do not generate gaseous products oxidation.

As is well known, various difficulties are encountered in the productionof magnesium by thermic reduction which make it impossible to carry outsuch a process in continuous manner on an industrial scale. The art hastherefore resorted to intermittent processes comprising the followingcycle of operations: charge of the material to be treated, heating ofthe material, distillation, condensation, and discharge of the resultantmagnesium and of the exhausted residu al material.

The magnesium distilling from the reaction zone is condensed in asuitable zone at a temperature of about 500"- In order to extract themagnesium from this zone, it is necessary to wait until'it cools to atemperature below 80-100 0., since otherwise the magnesium would reactwith the atmospheric air and be covered by a layer. of nitride and oxideor greater or less thickness,

quence ot'this arrangement is that, as soon as the thermic reduction hasbeen completed, the apparatus may at once be used for a new operation,as hereinafter explained.

' The aforesaid process may be the aid of the apparatus hereinaftercarried out with described and illustrated, solely by wayot example, inthe thereby greatly reducing the yieldgoi metallic magnesium.Thereaction with the air may be so violent that themagnesium may be seton fire and be totally converted into oxide.

In practice, the condensation zone is externally cooled. and thiscooling has to be continued even after the reduction reaction has beencompleted. However, this procedure, the object of which is to shortenthe duration of the period or cooling of the condensed magnesium, alsoincidentally cools the reaction chamber. This results in a considerableloss of heat'so that large additional quantities of heat have to besupplied during subsequent reduction operations, thereby unfavorablyafiecting the heat consumption.

The process of thepresent invention makes it possible to obviate, insimple manner, the aboveenumerated detects and disadvantages, and toreduce thermic losses and the time required for carrying out thewholeoperative cycle to a minimum. The present process is characterized bythe fact that the magnesium produced by the' thermic reduction isextracted in a condensation which is under a degree or vacuumsubstantially corresponding to the degree or vacuum prevailing in thereduction chamber, the condensation chamber being subsequently madeentirely independent of thereduction chamber. The consesingle flgureonthe accompanyin sheet or drawing The said figure of drawing is adiagrammatic longitudinal sectional view 0! the aforesaid apparatus, andreference character I. represents an electric furnace, 2 a heating coil,3 a reaction chamber, 4 a receptacle containing the reaction mass, I acondenser for the resultant magnesium, l a closure device for thecondenser 5, I means for controlling the closure device Ii, 8 a coverfor closing the outer end or the condenser 5 and the reaction chamber 3,and O a valved conduit leading to a vacuum-producing means (not shown).v

The procedure according to the present invention is as follows:

Theraw material, intimately mixed with the reducer and generallybriquetted, is charged into the receptacle 4 and introduced into the re-14 actionchamber I where it is heated under vacuum or at a reducedpressure at a temperature depending upon the type c! reducer employed.The evolved magnesium is condensedin condenser l. As soon as. thereaction ends, the closing device i is actuated by lever 1, cutting of!communication between the condenser E and the reaction chamber I. Thenthe wing nuts which afllx the cover 0 to the reaction chamber areunscrewed and the condenser I is removed, the ma nesium containedtherein undergoing no chemical alteration notwithstanding the fact thatit last a high temperature. The reaction chamber, after removaltherefrom oi the recep; tacle 4, may immediately be utilized again for anew operation by-fllling it with a new charge and removing the condenserI and thus permitting the immediate re-utilization of the apparatus, re-

sults in an appreciable reduction in the time of interruption or theproductive cycle. Moreover, the removal of the condenser containing themagnesium, according to the atoredescribed method, makes it possible toavoid supplementary cooling which, as above stated, is indispensableaccording to prior processes. while according to the prior processes thereaction chamber is cooled with the aidof a cooler annexed to thecondensation zone, this is avoided according tothe present inventionand, consequently, there is a substantial reduction in the quantity 01'heat which has to be supplied to the apparatus ior subsequent thermicreduction operations. In addition, no heat is lost as a result of longdelays during which the apparatus has to remain inactive, waiting forthe magnesium produced therein to reach -such a temperature that it maybe removed with no danger whatsoever oioxidation.

I claim:

A process for the production of magnesium by thermic reduction in areduction zone at reduced pressure, which comprises condensing the Theresult is that.'

evolved magnesium in a condensation zone juxtaposed to and incommunication with said reduction zone at a pressure substantially equalto that prevailing in the reduction zone, cutting 01! the communicationbetween the reduction zone and condensation zone while maintaining thejuxtaposition thereot whereby the atmosphere and pressure prevailing inthe condensation zone are rendered independent of the atmosphere andpressure prevailing in the reduction zone without change in suchpressure, and dissociating the condensation zone from said reductionzone whereby the latter may immediately be reassociated with anewcondensation zone, the pressure prevailing in the condensation zoneafter said dissociation being substantially the same as that prevailingin the system during the reduction'process.

- LUIGI AMATI.

